Commutator assembling and finishing device.



. No. 855,134. PATENTED MAY 2a, 1907.

J. RISBRIDGER.

GOMMUTATOR ASSEMBLING'AND FINISHING DEVICE.

' urmmnon FILED mm. 1, 1905. v

UNITED STATES JOHN RISBRIDGER, OF NORTH EAST, FIVE ONE-HUNDREDTHS TOEUREKA TEMPERED COPPER WORKS, OF NORTH EAST, PENNSYLVANIA, A CORPORATIONOF PENNSYLVANIA.

PATENT OFFIOE.

PENNSYLVANIA, ASSIGNOR OF FIFTY- COIVIIVIUTATOR ASSEIVIBLING ANDFINISHING DEVICE.

Specification of Letters Patent.

ratentea May 28, 1907.

Application filed December 1, 1905. Serial No- 289,920.

T0 whom it may concern:

Be it known that I, JOHNYRISBRIDGER, a citizen of the United States,residing at North East, in the county of Erie and State of Pennsylvania,have invented new and useful Improvements in Commutator Assembling andFinishing Devices, of which the following is a specification.

This invention relates to commutator assembling and finishing devicesand consists in certain improvements in the construction thereof as willbe hereinafter fully described and pointed out in the claims.

The invention is illustrated in the accompanying drawings as followsFigure 1 shows a central section through a I commutator with the devicein place thereon.

Fig. 2, a front elevation of the device on a face plate of a lathe. Fig.3, a section on the line 38 in Fig. 2.

A marks the face plate which may be of any desired form, ordinarilymounted on a bench; B, the commutator bars and these may be of anydesired form; I), the insulating material between them. A former O isarranged around the contact surface of the commutator bars. Preferablyit is in the form of a ring split diagonally at 0, there be ing a spaceat the opening a for compression or contracting the ring O. The outersurface 0 of the ring O is tapered and arranged on this tapered surfaceis a compression ring D having a tapered inner surface (I that registerswith the surface 0. The ring D is provided with a series of openings atand the plate A is provided with openings a that will register with theopenings 01 Bolts E are passed through the openings a and d and nuts eare arranged on these bolts by means of which the ring D may be forcedalong the tapered surface so as to contract the ring O and thus clampthe bars B and insulating material I) together.

Not only does the clamping ring D effect this compression but it alsocontrols the form of the ring C, so that its inner surface forms a truecylinder. This is efiiected by making the ring O flexible and preferablyelastic. Where the ring is elastic, and especially where it is made inone piece slightly larger than the clamped portion, it hugs the ring Dat all times so that its shape is, as stated, controlled by the ring Dand inasmuch as the ring D is of sufficient mass and rigidity tomaintain its shape under normal conditions of use the inher surface ofthe ring O as it is contracted maintains the form of a true cylinder.

After the ring D is in place it is secured by the set screws 1) whichpass through the ring D into contact with the former O. After the partsare secured as just described on the plate A, the nuts 0 are removed andthe ring D placed on a face plate F of the lathe. The face plate isprovided with the studs f having the extensions which register with theopenings (1 in the ring D. The extensionsf leave a shoulder on the studsf and nuts f are provided for clamping the ring against these shoulders.As these studs are arranged concentrically on the face plate the Outersurface of the assembled commutator bars are centered. so that all thatis necessary is to turn up the interior of the inner surfaces. Aftersuch surfaces as can be conveniently reached, as shown in Fig. 3, areturned the ring D may be reversed and other parts machined.

WVhat I claim as new is 1. In a commutator assembling and finishingdevice, the combination of a compression ring of suflicient mass andrigidity to practically maintain its shape under ordinary use, and acontractible former adapted to engage commutator bars arranged inannular form, said contractible former being ar ranged within thecompression ring, the former being comparatively flexible, saidcompression ring and former having engaging surfaces, the engagingsurface of one of them having a varying diameter to compress the formerby a relative movement of said surfaces in engagement, the former beingflexed and its shape maintained approximately a true circle as it iscompressed by the compression ring.

2. In a commutator assembling and finishing device, the combination of acompression ring of suflicent mass and rigidity to retain approximatelya circular shape under conditions of ordinary use, and a contractibleformer ring adapted to engage commutator bars arranged in annular form,said contractible former arranged within the compression ring, theformer being comparatively flexible, one of said rings being tapered Iand adapted to engage the other of said rings to contract the former assaid rings are moved relatively to each other in an axial direction, theformer being flexed and its shape maintained approximately in a truecircle as it is compressed by the relative movement of the rings.

3. In a commutator assembling and finishing device, the combination of acompression ring of sufficient mass and rigidity to retain approximatelya circular shape under the conditions of ordiary use, and a contractibleformer ring adapted to engage commutator bars arranged in annular form,said contractib'le former arranged Within the compression ring, theformer being comparatively elastic, the outer surface of the formerbeing tapered and the inner surface of the compression ring beingtapered in opposition to the surface of the former, said taperedsurfaces being in engagement and closing by actual movement of saidrings relative to each other the former, the former being flexed and itsshape maintained approximately in a true circle as it is compressed bythe relative movement of said rings.

4. In a commutator assembling and finishsssnsa ing device, thecombination of a compression ring of sufficient mass and rigidity tomaintain its shape under ordinary use, and a con.- tractible former ringadapted to engage commutator bars arranged in annular form, said formerbeing arranged Within the compression ring, the former beingcomparatively flexible, one of said rings having a tapered engagingsurface for acting on the other of said rings to compress the formerwhen said rings are moved relative to each other in an axial direction,and said com pression ring being provided. with a series of openingsthrough Which bolts may be passed for moving the same in an axialdirection to effect the compression of the former and which may be usedas a means of securing said compression ring for operating upon thecommutator bars.

In testimony whereof I have hereunto set my hand in the presence of twosubscribing Witnesses.

JOHN RISBRIDGER. IVitnesses:

O. MCKENZIE, M. A. SCOULLER.

